Controller for electric motors.



No. 695,H8. Patented Mar. I], I902.

R. H. READ.

CONTROLLER FOR ELECTRIC MOTORS.

Y (Applicaticn filec 1Ju1y 26, 1901.) (No Model.) 2 Sheets-Sheat I.

Fig.4.

JWWLE Inventor Robert. H. Read.

No. 695,||8. PatantedMar. |l, I902.

R. H. READ. CONTROLLER FOB ELECTRIC MOTORS.

(Application filed July 26, 1901.) (No Model.) 2 Sheets-Sheet 2.

FigS series v parallel rz54ss7 SSIOIIIZIiHvff reverse far-ward I gm!!! a \A/icnesses Inventor ru NORRIS PETERS co PHO10-L1THO. WASHINGTON, n. c.

40 but I prefer to employ compressed air for the ROBERT ll. READ, OF SOHENEOTADY,

PATENT OFFICE.

NFJV YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NE'W YORK.

CONTROLLER FOR ELECTRIC MOTORS.

Application filed July 26, 1901.

ASTIGN forming part of Letters Patent No. 69 5,118, dated March 11, 1902.

Serial No. 69,804. (No model To when], it may, concern:

Be it known that 1, ROBERT ll. READ, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements in Controllers for Electric Motors,(0ase No. 1,829,)013 which the following is a specification.

In the construction of controllers for variable-speed electric motors, particularly those employed in operating railway-cars, it is common to provide means for extinguishing the arcs at the contact-points of the controller for varying the resistance or changing the coup ling of the motors. This is commonly effected by inclosing the contacts between iron cheekpieces or pole-plates forming extensions of an electromagnet by which the arc is magnetically disrupted.

This invention relates to a new type of controller in which the arcs are extinguished pneumatically accordin to the principle described in an application for a United States patent filed by me, No. 54,122, dated April 3, 1901. in this type tubular contacts are employed and a stream of compressed air is forced across the coutact-faces and through the tubes when the circuit is broken, thereby effectually extinguishing the arc and reliev- 0 ing the contact edges of damage from pitting. In utilizing this mode of disrupting arcs in connection with a current-controller I provide a plurality of contact-boxes containing the tubular terminals and means operated by the controller-handle for governing the operation of the several boxes serially or in any definite order to ettect the desired circuiting of the motors and regulation of their speed. This control. may be ctany desired character;

In the accompanying drawings, which illus trate the invention, Figure 1.is a sectional view of a pneumatic controller embodying my improvements. Fig. 2 is a diagram of such a type of controller as applied to a street-railwaynnotor outfit. Fig. 3 is a sectional view of one of the contact-boxes. Fig. at is a sectional view of one of the valves for delivering air-pressure to the contact-boxes. Fig. 5 is a development of the casing of the valvechamber, showing the arrangement of the delivery-ports. Fig. 6 is a sectional view of a controller, showing the arrangements of the pipe connections between the valve-box and the several contact-boxes. Fig. 7 is a plan view of the valve-box with the cover removed. Fig. 8 is a central sectional view of the valvebOX. Fig. 9 is a sectional detail of the controller-handle and its connected parts; and

Fig. 10 is a detail view, on a reduced scale, of the valve-box for the reversing-switch.

I provide a plurality of contact-boxes of the type shown in Fig. 3 for making and breaking the contact in the several controller positions. Each of these boxes contains tubular metallic contacts 1 2, one having a tapering and the other a flaring nose by which they may be brought together and effect a reliable contact. They may, if desired, be split or otherwise constructed, so as to make a close sliding fit. One may be fixed in a metal casing and the other be mounted so as to slide therein, as indicated in the drawings.

The casing may be lined with asbestos or fiber, preferably a material which is heat" refractory as well as insulating. The joints should be fairly tight, so as to avoid excess ive leakage. The movable tube may carry a piston 8, sliding loosely over the lining and 0 provided with a small hole l to guard against accidental operation due to leakage of air. The casing at or near the ends is provided with nozzles 5 5, from which extend pipe connections to a valve-box, presently to be 5 described. The movable tube has a cooperating spring'latch 6 to hold it in its open position and prevent jolting loose, the latch being so designed as to permit the tube to be driven forward to a closed position when air 103 is supplied behind the piston-for example, through the nozzle 5. As many of these contact-boxes as desired maybe provided to afford a smooth graduation of speed in the motors. As shown in the drawings, I have provided ten contact-boxes, mounted one above another in a controller-casing on an insulatingsupport 7. The casing is preferably lined with non-conducting material, such as fiber or wood, and the boxes separated from one another by dividing insulating-partitions, as 8. The opening and closing nozzles 5 5 of each box connect by aclosed pipe or conduit with a valve box or casing 9. These pipes may be made of soft rubber and connected tact-boxes.

in a bundle, as indicated in Fig. 6, each pipe branching at the top and connecting the two branches respectively with the upper and lower section of the valve-casing 9. This valve-casing is a cylindrical chamber provided with a series of openings arranged in circular order on its periphery and connecting with the several pipes leading to the con- The supply-pipe for compressed air connects with a nozzle 10, communicating with a tubular shaft of the valve-casing, in which operates in a ground seat a stem 1.1, to which is connected the controller-handle 12.

The stem 11 is counterbored and provided with two lateral openings 13 13, angularly displaced relatively to one another. The controller-handle is allowed a certain amount of free motion with respect to the hollow shaft inclosing the stem 11 sufficient to permit one of the ports, as 13, to be covered by the wall of the socket, while the other is in open relation to its spring-pressed valve. The valvecasing is divided by'a partition 14. into an upper and lower chamber, each of which contains a spring-pressed tubular valve 15 15, having a face sufficiently wide to couple two ports leading to the contact-boxes. A starwheel 16 may be attached to the controllerhandle and a spring-check 17 be provided as usual to arrest the operation of the controller at definite angular positions. The valves 15 15 should have a true fit against the inside ofthe casing and should be pressed into their seats by a stout spring to maintain a tight joint.

With the construction as thus organized it will be evident that in'turning the controllerhandle-sayupwardly, as depicted in Fig. 7-- the handle willfirst take up the lost motion, moving through the slot or recess 18, during which the valve-stem 11 will be turned in its socket, so as to expose one delivery-port and cover the other. This relation is shown in Fig. 8, where the valve 15 is shown in open relation to the supply-pipe 10 and valve 15 is out of communication, the port to the lower valve 15 being covered, as indicated by dotted lines at 13. A further movement of the controller-handle will then shift the socket and both valves; but valve 15 being alone in communication with the air-pipe only that row of pipes communicating with the upper chamber ofv the casingwill receive pressure. During a continuance of the handle movement the air-pressure is successively delivered to the groups of pipes entering the wall of the casing. Fig. 5 shows a development of these openings and also the manner in which they may be cut in to operatetwo railway-motors in series and parallel relation. As the controller-handle is turned air is put on contactboxes No. 1 and No. 9 first through nozzles 5 so as to close the contacts in each. This is represented in Fig. 5 by the reference-numerals l and 9, indicating that boxes No. 1 and No. 9 will be closed when pressure is delivered at that point in the casing. A further movement of the handle closes contactbox No. 2. A further movement closes contact-box No. 3 and opens contact-box No. 1, as shown at 1. A further movement closes contact-box No. 4: and opens No. 2, as seen at 2. Thus it will be evident that any desired sequence .of connecting operations may be eifected by a suitable grouping of the boxes and the several'supply-pipes connecting with the valve-chamber. I preferably provide also a reversing switch or controller operated in the same manner as the main controller and connected with the same air-pipe 19, conmating with the train-pipe or auxilary reservoir. The valve-casing for this controller is so arranged that in either a forward or reverse position communication will .be established between the air-pipe 19 and branch 19, leading to the valve-casing 9, but in an open position of the reversing-switch air will be cut ofi. In other words, the reversing-switch and main controller are connected .in series relation in such a way that the main .controller is disabled from operation exceptwhen the reversing-switch is .closed for either for-, ward or backward movement of the motors. This feature of construction of the reversingswitch is indicated in Fig.4. But a single valve-chamber is necessary, as there is no change in the sequence of operations.

When the reversing-switch stands in an open position, a movement either to the right or left with respect to this position will efiect the connections, so as town the motors forward or backward. reversing-switch its valve completes'the con- In each position of .the'

nections between the train-pipe 19 and two pipes 20 and 20, Figs. 4 and 10, the latter of which branches and leads to a pair of contactboxes ab or ad.

There are two steps for each position forward or backward of the reverser, the delivresistances for graduating the speed of the motors 22 22. These resistances connect with the source of current through the several contact-boxes No. 1, No. 2, No. 3, No. l, No. 5, No. 6. Box No. Tleads directly to the motor without inclusion of resistance, and boxes No. 8, No. 9, and No. 10 are arranged to connect the two armatures 22 and 22 in parallel. 23 represents a trolley, and 24 an automatic circuit breaker, which may be hand-operated to permit opening of the circuit in case of failure of air. Assuming that the reversing-switch is in a position to close contact-boxes a and Z) and that contact-boxes No. 1 and No. 9 are closed, the two motors will be connected in series through maximum resistance over the following circuit: from trolley 23 through the circuit-breaker 24, through the motor-fields in series by lead 25, through contact-box a by lead 26, through contact-box 1 of the main controller, through resistance 21, armature of motor 22, contactbox 9, armature of motor 22, lead 27, contact-box b, and lead 28 to ground. Thus the motors are started with a maximum resistance. In the next position of the controller,

as indicated in Fig. 5, contact-box No. 2 is closed, 9 still staying on, thereby cutting in the resistance 21 in parallel with resistance 21, and thus by consecutive movements of the controller the boxes No. 3, No. 4:, No. 5, No. 6 are consecutively cut in, speeding up the motors. As shown in Fig. 5, when box No. 3 is closed No. 1 opens, and when No. 4 closes N0. 2 opens, this order of progression being maintained until the final step of the series position, when boxes No. 6, No. '7, and N0. 9 are closed. The next step opens all boxes, and the armatures are then thrown in parallel by closing boxes No. 1, No. S, No. 10, the circuit being as follows: As before, to contact-box No. 1, thence to resistance 21, where the current divides, one branch passing through armatnres of motor 22 and contactbox 10 to the point 30 and the other branch passing over conductor 29 to box No. 8 and armature of motor 22 to the point 30, and proceeding thence by 27 and contact-box b of the reversing-switch to the ground. By a subsequent change of grouping of the contact-boxes the resistance in the parallel grouping is gradually cut out and two motors ultimately connected in simple parallel. A final row of ports, as indicated at the end of the development in Fig. 5, is provided for opening the parallel connections and instantly disconnecting the motors. This operation may be conducted with entire safety in a switch provided with arc-extinguishers of the kind herein described. For ordinary operation, however, the controller-handle will be turned backward in slowing down the motors, during which a reverse order of connections is made in the contact-boxes, as indicated in the lower panel of the developed diagram in Fig. 5. Since in a forward movement of the controller-handle the boxes were closed in a definite order, several being held closed at the same time, the grouping of the ports must be different for a retrograde movement of the handle. in starting such retrograde movement the valve connections are changed so as to bring the dotted port 13, Fig. 8, into action and close the port 13. This cuts off valve 15 and brings into action 15. The pipes in the lower chamber are arranged in the order indicated in the lower panel of Fi 5. The several steps will gradually cut in resistance until a position is reached at which boxes No. 6, No. 7, N0. 9 are closed, thereby putting the motors in series. The successive steps then gradually cut in resistance until a maximum amount is cut in, after which the circuit opens on boxes No. 1 and No. 9.

The reversing-switch might, if desired, be of the usual construction. The arrangement described permits instantaneous reversal for emergency use.

What I claim as new, and desire to secure by Letters Patent of the United States, is-

1. An electric controller comprisingasource of fluid-pressure, a plurality of pressure-operated contacts for progressively varying current strength, and means for coupling said contacts in different order by a forward-andbackward controller movement.

2. An electric controllercomprisingasource of fluid-pressure, a plurality of pressure-operated contacts, a handle for operating the contacts in groups, and means for changing the groups in forward-and-baekWard movement of the handle.

3. An electric controller comprising a source of fluid-pressure, a plurality of pressure-operated contacts in different circuit relations to translating devices, a handle for grouping the contacts in closed relation to progres sively increase current on starting, and means for changing the groups during a reverse handle movement to progressively decrease current.

l. An electric controller comprising a source of fluid-pressure, a plurality of pressure-op erated contacts in different circuit relations to translating devices, an operating-handle, a valve-chamber and means for delivering air from said valve-chamber to alter the contact closure by a forward or backward operation of the handle, respectively.

5. An electric controllercomprisinga source of fluid-pressure, a plurality of pressure-operated contacts in different circuit relations to translating devices, a duplex valve-chamber having pipe connections with the pressurecavities of the contacts, the grouping for the contacts being different for the two parts of said chamber, and means for delivering pressure from one chamber or the other by forward or backward handle movement.

6. An electric controller comprising a source of fluid-pressure, a plurality of contacts each adapted to extinguish the are by fluid-pressure on opening the circuit, andcontaining a duct to confine the arc-gases, and means for operating the contacts in a determinate order.

7. An electric controller provided with a plurality of contacts for varying the circuit connections with a translating device, means for operating the contacts in a determinate order, a source of compressed air, means for delivering air across the several contacts when they open, and a duct to receive and confine the arc-gases.

8. 'An electric controller provided with a plurality of tubular contacts for varying the circuit connections with a translating device, means for operating the contacts in a determinate order, and means for causing a blast of air in the tubes when the contacts open.

9. An electric controller provided with a plurality of tubular contacts, pressure-operated devices for closing and opening them, means for causing air-pressure in the tubes when they open, and a valve for operating them in determinate order.

10. A circuit-breaking box comprising tubular contacts, a casing around the same, a fluid-pressure pipe opening into the casing and a piston for separating the contacts.

11. A circuit-breakin g box comprising separable contacts, a casing inclosing them, a fluid-pressure pipe opening into the casing, means for directing said pressure across the contacts, and a piston for separating the contacts.

12. .A circuit-breaking box comprising separable tubular contacts, a casing inclosing the same, a piston connected to the movable contact and means for applying fluid-pressure to close and open the contacts and extinguish the arc.

13. A circuit-breaking box comprising tubular contacts, a casing inclosing them, and

duplex valve-chamber, independent groups of ports for each section, valves governing admission of air-pressure, and a lost-motion connection with the operating-handle controlling supply of air to the valves by a forward or backward movement, respectively. 16. A pneumatic controller comprising a plurality of air-operated contacts governing the motor connections, and means controlled by the reversing-switch governing admission of air to the contacts. 7

17. A pneumatic controller comprising an air-controlled reversing-switch and controller, and connections for leading air to the controller through the reversing-switch.

In witness whereof I have hereunto set my hand this 24th day of July, 1901.

ROBERT H. READ.

Witnesses:

BENJAMIN B. HULL, $FRED Russ. 

